Concentration and Flow Measurement of Caustic Soda

One of the products of the chlorine-alkaline electrolysis is a watery Sodium Hydroxide (NaOH) solution. Normally this diluted solution is condensed in a multi-stage distillation process to a commercial concentration of 50%. In order to ensure the specified quality / concentration is maintained at all times, is has to be measured continuously.
Conventionally used Coriolis meters are subject to enormous wear and tear by the aggressive medium and are thus prone to measurement drift making frequent recalibrations necessary. Moreover, in case of a meter failure, its replacement is very costly as a shutdown of operation for several days is required in order to shut off and empty the pipeline.

Non-invasive measurement with the PIOX S clamp-on ultrasonic mass flow meter and concentration analyser proves to be the superior solution. It determines the NaOH concentration by measuring the speed of sound. Since the clamp-on ultrasonic transducers are simply mounted on the outside of the pipe, they are not subjected to any wear and tear by the aggressive medium. Non-invasive measurement is therefore stable in the long term and shows no measurement drift. As a result of the continuous accurate concentration measurement, plants can be run with optimum efficiency at all times, maintaining the specified product quality. Moreover, PIOX S also measures the mass flow rate of the flowing medium.

Advantages

Accurate and reliable mass flow and concentration monitoring

Virtually maintenance free and very durable

Ensuring reliable, continuous process control

Non-invasive measurement from outside the pipe means:

- Very easy to set up the measuring point without opening the pipeline
- No risk of leakage
- No wear and tear by the aggressive medium
- No expensive special materials required
- No measurement drift
- Plant availability is not impaired in any way